import time

DATE_FORMAT = "%Y-%m-%d"
TIME_FORMAT = "%H:%M:%S"
DATETIME_FORMAT = "%Y-%m-%d %H:%M:%S"

DATE_FORMAT_STR = lambda fmt=DATE_FORMAT: time.strftime(fmt, time.localtime())
TIME_FORMAT_STR = lambda fmt=TIME_FORMAT: time.strftime(fmt, time.localtime())
DATETIME_FORMAT_STR = lambda fmt=DATETIME_FORMAT: time.strftime(fmt, time.localtime())